Sponge holder



FIG. 1 is a front elevational view of a sponge holder showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof, the right side being a mirror image thereof; and,

FIG. 4 is a top, front, and left side perspective view thereof. 

The ornamental design for a sponge holder, as shown and described. 